Firing Blanks With Laser Tag

Last year, [Tony] was asked to develop a lasertag system with ultimate realism. This meant a system that used a blank firing replica gun, and a system to detect blank rounds being fired. Very cool, and the way he went about it includes some interesting electronics.

Because the system requires a blank to be fired before shooting a laser at a target, the entire system must be able to detect a blank being fired. [Tony]’s first attempt used a piezo sensor to detect the shock from being fired. This system had a lot of noise and was ditched for a much better solution: a magnet mounted to the slide, and a hall effect sensor mounted to a 3D printed frame that turns this replica into a carbine.

A little bit of tweaking in software was required to inhibit the laser when the operator cocks the gun, but it looks – and sounds – really good. It’s also very, very realistic: the only way to shoot an opponent is to physically reload. Video below.

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37 thoughts on “Firing Blanks With Laser Tag”

There are commercial versions of this, the Swedish military uses one of them, a laser package that clips onto the barrel of the carbines and rifles used. These use a proprietary sound sensor to detect a blank being fired. Some soldiers realized that you don’t actually have to fire the sniper rifle, all you need to do is tap the barrel with a metal tool to fire the laser without making the sound of a shot and having your position found…

I believe later versions detect the extremely high gas pressures near the barrel exit.

They also do training with “simunitions” which are basically chalk bullets fired out of reduced-power cartridges, basically paintball’s meaner brother. They require modifications to the guts of the weapons, both to allow them to properly cycle with the weaker cartridges and to prevent a training gun from accepting a live round.

Simunitions kits are easy to get and a LOT cheaper to use. They cover the AR-15 and other very popular guns that the military and LEO use.

Civilians can not buy the systems because the average IQ of the population is so low that a bunch of idiots will buy this system and go have a firefight in their local woods, the cops will show up and kill several of them.

Well, given an instance of cops shooting less lethal rounds directly at citizens heads resulting in the death of Victoria Snelgrove and other instances (that I have personally witnessed) of police using less lethal weapons in a potentially lethal fashion, I question the IQ if the average law enforcement officer in addition to the general public.

On a random aside, the field photographer standing next to Victoria Snelgrove when she was shot was Dan Bersak, fellow maker enthusiast. Dan took a lot of flack for recording the event instead of helping her, even though it was clear she was dead, and he was completely incapable of doing so anyway due to the amount of camera gear literally strapped to him. Bizarrely, people sent him death threats over something that wasn’t his fault and beyond his control.

Some years after the event, Dan became a robotics PhD student at Yale (which is where I met him). Dan is an amazing guy who skydives, flies helicopters, is a trained EMT and was on the MIT shooting team. Today he’s a special projects manager at Makerbot.

Interesting anecdote. That makes me wonder how the real shot shot spotter systems differentiate between something like a gas powered nail gun or fireworks or (in light of the barrel tap) something like the sharp rap of a hammer on something.
Is it the wave form or a frequency thing?
i.e. needing a projectile in the air to create a noise shape, say maybe it has to be super sonic and create a certain Doppler effect to be flagged as a gunshot in order to trigger the alert for “shot fired”
or the super sonic creates a known frequency that is the trigger??
Sorry for going so far off topic, this just stirs my curiosity
and curiosity is why I come here.

I’d think its really a waveform thing, that a gunshot noise has a faster rise than a firecracker due to the higher velocities. Also the gas leaving the barrel, vortices at the muzzle and stuff are propably detectable by good mics.
Then gunshots have the crack of the supersonic bullet flying in addition to the shot’s bang (crack-bang method to estimate a shooter’s distance).
See http://en.wikipedia.org/wiki/Gunfire_locator

Interesting reading, especially tracking the air friction heat signature of the projectile (could cover some coil guns I guess). The last time I looked, the info was proprietary/too guarded to show up in a wiki page.
I live in a city that installed some sort of monitors (undisclosed type)
and I noticed the gang-bangers in the area seemed to almost stop all the in-discriminant late night, “emptying a clip” non-sense in a matter of a few weeks.

For me as a German, it is quite unbelievable to have a city installing gunshot trackers because gangsters shooting around (I also read Chicago disemployed the systems because of too many false alarms).
Regarding false positives: I think they are much more common in dense urban environments where there are difficult to model surroundings, echos for example, while the military models are designed for more open environments (optical sensors wouldn’t work without direct LOS) and also have more sophisticated algos and sensors than civilian models.

On the subject of laser tag, has anyone been actually able to use their own microcontroller with an IR LED to trigger the Light Strike targets?

A few days ago I bought 20 WowWee Light Strike Targets for 29p each (bagains shop was having shifting old stock) because the components they have inside were worth it, but I’d like to actually get them working with my own custom gun, and it would be beneficial to use the existing circuitry than spend money on putting my own microcontroller inside them.

Home Bargains, not sure if was just a local branch that got some stock cheap to get rid of or not.

In theory yes playing back the IR codes will trigger it but I’m half stabbing in the dark as I don’t have an official gun to trigger them with (they’re quite expensive) and then I’d need an accurate way of recording the signal. Perhaps it’s time I hunt down an oscilloscope.

I would activate the LASER when the trigger is pulled, put a one shot on it so it’s not on the whole time.
Because if you’re relying on anything else, you’re not going to get the accuracy you should. Even a blank will either cause the gun to jerk, or the shooter will jerk it. Plus, in a real gun, the bullet doesn’t fire after anything happens, it fires when you pull the trigger.
I like it, I like the idea of more realism. This could be a good way to save on ammo at the range. But, I get kinda nervous with any gun that is “supposed to fire blanks” without proper systems in place to make SURE it fires only blanks.
Too many people have been liquidated by some nitwit putting a real bullet in there or some other projectile that acts like a real bullet when a blank is fired.
But I would think as far as blanks go, the .22 shorts would be just fine. Or the ones they use in the concrete hammers. Plenty loud enough, cheap enough, and not all that much “power” compared to say a .40 or .45. As long as you’re modifying the gun to this extent, might as well design it to shoot these. (I think the concrete hammers use a modified .22, not sure what it is with those)
I use a suppressor anyway, so the sound isn’t a big deal for me, I want quietness on the range. (so a CO2 “pop” would be more realistic for me)
Just my 2 cents on it.

remember, though, that the point of this build is to simulate the “real world” accuracy-which means it SHOULD react to the flinch of trigger pull and the recoil jerk. It would be more accurate to fire the laser at trigger pull but would not simulate where the round will actually go when fired.

Another idea for a later build would be using a laser rangefinder that calculates distance at the moment of firing, in such a manner that either the target, or some sort of “steering” at the gun’s laser emitter, calculates for bullet drop based on the load it’s programmed to simulate.

this way his training device becomes multi caliber through a simple slide and magazine change for feeding the blanks, and a selection in the firmware.

Would a photosensor (would need lots of cleaning) or a thermocouple be fast enough to read the blank firing from the heat of the round’s gasses?

Just a quick note about blank firing pistols. My first thoughts were of Jon Eric Hexum from the voyagers TV series that killed himself by firing a prop blank pistol at his head, acting as though he was committing suicide. It wasn’t planned that way of course, but it’s a reminder that blank ammunition also doesn’t automatically mean that it’s safe and harmless.

^^ important stuff up there. Blanks use a wadding that has significant velocity at barrel exit. And a lot of the cowboy shooters (SASS) use florist foam as a wadding. SASS demonstrates this at their shows by firing at an aluminum soda can at 6 inch standoff.

Shreds the can.

Also remember, that for safety sake, consider that all weapons are loaded with live ammo.

I had to try and develop a very similar system, for use in a stage show. The client wanted to take some toy “cap” guns (revolvers), and have the action of firing trigger some squibs placed across the room.

I ended up using a reflective strip around the revolving cylinder, along with a IR photo-reflective sensor mounted in the frame. This was fed into an interrupt pin on a ‘TINY 4313, which then fired off a packet from a nRF24L01+ module.

Worked wonderfully on the bench; not so nicely in the field though! You’d be surprised how much RF noise there is floating around a music festival site; The signal from the nRF’s was completely lost at any distance greater than a few inches.

I’m looking at modulated IR to provide feedback in the next iteration, low power RF is definitely not the way to go in that sort of environment!

You would probably have better luck with either a lower frequency or a directional antenna, or both. Preferably combined with much higher power, those 24L01 chips are basically the weakest transmitter you could buy :P

IR is good indoors in a normal environment but is easily drowned out by sunlight outdoors or when large studio lamps are used.

I agree, lower frequency would probably have had a better chance, coupled with higher power. We were working within 20m of a 50kVA generator set, so I can only imagine how much RFI that was kicking out.

We did have the benefit of a closed set (indoors), so I think IR is definitely the way to go the next time!

At the local gun range they replaced the magazine with a CO2 cartridge to simulate the *bang* and just replaced the entire firing mechanism with a laser. This way they just had to fill the CO2 cartridges after ~50 shots and not have to bother with blanks. Of course, they did have to completely rebuild the firearms, so pick your poison.

Otherwise, your hack looks really cool. I just might suggest that you modify the slide so it can NOT accept a non-blank round. Remember rule #1 of firearm, “A gun is always loaded.”

I hope this isn’t in the US. There are severe penalties for manufacturing a short barreled rifle (e.g. attaching a buttstock to a pistol) without the proper tax stamps. If you want a rifle (or rifle like carbine) make sure that it’s at least 26″ long with a 16″ barrel (that’s federal law, state law may be different).

Can’t understand the point of shooting whatsoever if it has a laser tag..

It’s like a redundancy system? if the bullet isn’t supposed to hit you, is it only to make noise? then what’s the point of having the bullet.. i’m confused or i didn’t get the question, plus there is an old “toy” i think it is not a toy anymore called airsfotf guns in case people really want to shoot something.

It’s a simulator for actual firearm training where safety and cost are a concern. It also, with proper development, allows all the fun of actual firearm practice but with vastly reduced legal issues.

If this device in its final form cannot ever be made into a legally defined firearm, then range day can allow simulated automatic weapons that make all the visceral noise and still require all the actual skill to hit stuff.

There seems to be a bit of confusion as to what ‘blank firing’ means in relation to UK law. I’ve appended a paragraph to the bottom to explain. But to summarise: The barrel is blocked, no gasses or wadding or anything leave the muzzle.